Modern semiconductor devices are typically packed with higher density of transistors and transistors with shorter channel (gate) lengths to increase the operating speed and performance of the devices. Short channel effects exhibited by modern semiconductor devices typically limit the performance of the devices. Transistors with higher channel lengths are typically designed to mitigate the short channel effects and off-current leakage. However, such design typically requires larger pitch size between transistors and compromises high die area utilization.
Recessed channel array transistors (RCAT) have typically been used where low leakage or low variation of current leakage is critical, such as in analog and memory devices. A RCAT typically demonstrates better short channel effects relative to conventional transistors, such as non-planar (logic) and multi-gate transistor devices. Compared to a conventional transistor having the same layout gate lengths a RCAT typically includes a longer effective gate length, and significantly lower subthreshold slope (SS) and drain-induced barrier lowering (DIBL) voltages, hence lower off-current leakage and a more controllable voltage variation.